Worked on stabilizing calendar integration for the thunderbird/appointment repository by addressing CalDAV connectivity issues in Dockerized environments. Focused on improving cross-container communication, the solution involved configuring extra_hosts in YAML to allow the application container to reliably reach the CalDAV service using a stable hostname rather than localhost. This adjustment enhanced deployment reliability and ensured consistent calendar access in production-like setups. Leveraging skills in Configuration Management, DevOps, and Docker, the work reduced deployment friction and clarified the networking approach through detailed documentation in the pull request, resulting in a more robust and maintainable containerized calendar integration workflow.